JPS6261765A - Roller apron for continuous casting - Google Patents

Abstract

PURPOSE:To improve production efficiency by dividing the rolls of a roller apron to at least three parts and separately providing respective frames, driving devices and stoppers to the central roll and the other divided rolls. CONSTITUTION:The roller apron is formed of an outside frame 3, central frame 4, divided rolls 5A, 5B, actuators 1, 2 and stoppers 7, 8. The central frame 4 fixing the central divided roll 5B is slid independently from the outside frame 3 so that respective roll gaps can be adjusted to an optional thickness in the case of casting a dogbone slab. Pressing force to withstand the plastic deformation resistance of the solidified shell of the ingot is provided to the actuator 2. The need for changing a pass line passage for each of the products is eliminated by such mechanism, by which the generation of loss time is prevented. The production efficiency is thus improved and the energy is economized.

Description

[Detailed description of the invention] <Object of the invention> Industrial application field The present invention relates to a roller apron for continuous casting, and in detail,
without having to rearrange the mold or slab pass line passage.
This invention relates to a roller apron for continuous casting from which slab slabs or beam blank slabs can be obtained.

Conventional technology When continuously casting slabs with an H-shaped cross section, for H-shaped steel with a relatively small cross section, the rectangular mold and roller apron of the bloom continuous caster are replaced with the mold and roller apron exclusively for beam blanks. A technique for replacing and casting has already been proposed (Japanese Patent Laid-Open No. 199555/1983). However, due to equipment constraints, large cross-section rectangular slabs are broken down in a rough mill to approximate the shape of the H-shape (dogbone), and then H-beams are produced in a shape steel mill. It is common practice to finish the Whichever method is adopted, there are problems such as loss time for replacing the mold roller apron, restrictions on the instruction set, etc.
Alternatively, since the number of baths during rolling increases, the unit consumption of the heating furnace is high and the yield is poor, resulting in many problems in terms of efficiency, energy saving yield, etc.

As a solution to these problems, Japanese Patent Application Laid-Open No. 57-589
No. 134, No. 57-195509 has been proposed.

JP-A No. 57-58964 discloses that a predetermined beam blank slab is obtained by pressurizing and forming a slab used from a mold in an unsolidified state;
No. 509 is a method in which a solidified slab that has undergone secondary cooling is rolled down from both the front and back sides of the slab by a rolling machine to obtain a slab of a predetermined shape.

However, the former machine has problems in terms of economic efficiency because it is a machine exclusively used for beam blanks, and there are also difficulties in controlling the position of the forming rolls. Therefore, the rolling load becomes excessive, and there is a problem in that it is difficult to achieve a large reduction when directly connected to a continuous casting machine with a low drawing speed.

Problems to be Solved by the Invention The present invention aims to solve these problems, and specifically, divides each roll of the roller apron constituting the slab passage and changes the rolling reduction amount of each roll. It is an object of the present invention to provide a roller apron for continuous casting that is configured to enable production of both slab slabs and beam blank slabs.

<Structure of the Invention> Means for Solving the Problems and Their Effects The present invention provides for continuous casting of steel in which each roll of a roller apron constituting a slab passage or rolls spaced apart at a predetermined interval are connected to at least three rolls in the width direction. The present invention is characterized in that the center divided roll and the other divided rolls are arranged in respective frames, and each frame is provided with a driving means and a stopper for limiting the amount of driving.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration and operation of the present invention will be explained below with reference to the drawings.

FIGS. 1(a), (b), and (C) are a plan view of the roller apron of the present invention, a sectional view taken along arrow A-A, and FIG.
2 is a cross-sectional view of alignment in the case of casting a dogbone slab.

The main configuration of the continuous casting apparatus according to the present invention is as follows.

(1) The roll and roll support frame can be divided as necessary, and the roll and frame can be driven together using hydraulic or electric driving means to form any path line.

(2) When casting dog-bone slabs, the roll gap at the center of the slab is gradually narrowed from the upper roller apron in the secondary cooling zone of the continuous casting machine, so the static iron pressure of the molten steel and the plastic deformation resistance of the solidified shell are reduced. Must have a drive device with a pressing force greater than or equal to the above.

(3) Each divided frame has a spray header for cooling the slab and a plurality of sprays, and moves in unison with the roll and frame.

(4) Attach a positioning stopper to each divided frame.

That is, the roller apron of the present invention shown in FIG.
two frames 3.4, divided rolls 5A and 5B fixed to each frame (Fig. 1 shows three divided rolls), an actuator 1.2 for driving each frame, and a stopper for preventing slab reduction. 7.8 (frame positioning stopper), a spray header fixed to the frame, and a slab cooling spray (the spray header and spray are not shown). The central frame 4 that fixes the centrally divided rolls 5B slides independently of the outer frame 3, and when casting dogbone slabs, it is possible to adjust the roll gap to an arbitrary thickness. This central frame is restrained by guides 9 provided on the outer frame, and prevents the path line of the central frame portion from going out of order due to reaction force when supporting the slab by rolling down. Furthermore, the actuator 2 for pressing the frame has a pressing force sufficient to withstand the plastic deformation resistance of the solidified slab shell and the static iron pressure of molten steel, and
A stopper 8 is provided to restrict the extrusion teeth of the split roll 5B during production of the beam blank. Therefore, this stopper 8 prevents the slab from being excessively rolled down by the split rolls 5B. The rolling reduction amount of the divided rolls 5B arranged at a predetermined interval is set so as to gradually increase slightly from upstream to downstream depending on the degree of development of the solidified shell.With this setting, the rolling reduction is repeated with each divided roll 5B, and the mold is The slab pulled out from the slab undergoes a cumulative reduction and assumes a predetermined shape. The amount of reduction is set by the stopper 8, and is carried out to prevent breakage of the coagulated shell, such as breakout. The subdivision roll 5A is used as a roll that supports the fillet portion of the beam blank.

In addition, when casting a steel type that is prone to cracking, or when the cumulative reduction amount by the split rolls 5B cannot reach a predetermined value, the reduction may be applied at the pinch roll portion or the completely solidified portion. In this case, it is possible to take a larger value than the unsolidified remaining part, and there is no problem even if a reduction value of 10% or more is taken with one stage of reduction rolls, and it is an operation to replenish the insufficient reduction amount. Therefore, simple equipment is sufficient.

In addition, in the case of continuous slab casting, the dividing roll 5B is placed at the same position as the subdividing roll 5A, and casting is performed as a single roll.

Example This will be further explained below using examples.

When manufacturing a dog bone slab using the roller apron of the present invention, as shown in FIG.
Rolling down is performed sequentially by changing the roll gaps A and 8 of 5B.

That is, the roll gap is set so that the amount of rolling of the slab that has passed through the rectangular cross-sectional mold increases sequentially from upstream to downstream at the roller apron. This setting side is shown in Table 1. Table 1 also shows the roll gap setting side when casting a rectangular slab with equal roll gaps between the split rolls 5A and 5B, and the roll gap setting side when casting a dog-bone slab. In the case of a Tsugbone slab, the mouth-to-le gap A is set to the same roll gap as in the case of a rectangular slab, and B is the O-ru gap from 225.2 mm to 134.4 mm from #10-la apron to #90-la apron. Set to decrease sequentially.

By setting the roll gap in this manner, a desired dogbone slab can be obtained without causing breakage of the solidified shell such as breakout. Each roll or rolls spaced apart at a predetermined interval are divided into at least three parts in the width direction, and the centrally divided roll and the other divided rolls are arranged in respective frames, and each frame is provided with a driving means and a stopper. The roller apron for continuous casting is characterized by the fact that by configuring it in this way, it is possible to obtain slab slabs or beam blank slabs without casting or rearranging the slab pass line passage, which is different from the conventional roller apron. Problems such as loss time due to replacing molds and roller aprons and restrictions on assembly instructions are eliminated, so there are significant benefits such as improved production efficiency and energy savings.

[Brief explanation of drawings]

FIGS. 1(a), (b), and (C) are a plan view of the roller apron of the present invention, a cross-sectional view taken along arrow A-A, and arrow B.
-8 direction sectional view, FIG. 2 is a sectional view of alignment when casting a dog bone slab. Code 1... Frame pressing cylinder (actuator) 2... Frame pressing cylinder (actuator) 3... Frame 4... Frame 5... roll

Claims (1)

[Claims] In continuous casting of steel, each roll of the roller apron constituting the slab passage or the rolls spaced at a predetermined interval are divided into at least three parts in the width direction, and the center divided roll and the other divided rolls are arranged in each frame. On the other hand, a roller apron for continuous casting is characterized in that each frame is provided with a drive means and a stopper for limiting the amount of drive.